The page module in TYPO3 before 8.7.11, and 9.1.0, has XSS via $GLOBALS['TYPO3_CONF_VARS']['SYS']['sitename'], as demonstrated by an admin entering a crafted site name during the installation process.
Severity
CVSS 3.0
4.8 medium
CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
EPSS
2.2% chance of exploitation in the next 30 days; higher than 82% of CVEs (scores of 2026-10-31)